Buggy code:
public class IabHelper { boolean mDebugLog = false ; String mDebugTag = "IabHelper" ; boolean mSetupDone = false ; boolean mDisposed = false ; boolean mSubscriptionsSupported = false ; boolean mAsyncInProgress = false ; String mAsyncOperation = "" ; Context mContext ; IInAppBillingService mService ; ServiceConnection mServiceConn ; int mRequestCode ; String mPurchasingItemType ; String mSignatureBase64 = null ; public static final int BILLING_RESPONSE_RESULT_OK = 0 ; public static final int BILLING_RESPONSE_RESULT_USER_CANCELED = 1 ; public static final int BILLING_RESPONSE_RESULT_BILLING_UNAVAILABLE = 3 ; public static final int BILLING_RESPONSE_RESULT_ITEM_UNAVAILABLE = 4 ; public static final int BILLING_RESPONSE_RESULT_DEVELOPER_ERROR = 5 ; public static final int BILLING_RESPONSE_RESULT_ERROR = 6 ; public static final int BILLING_RESPONSE_RESULT_ITEM_ALREADY_OWNED = 7 ; public static final int BILLING_RESPONSE_RESULT_ITEM_NOT_OWNED = 8 ; public static final int IABHELPER_ERROR_BASE = - 1000 ; public static final int IABHELPER_REMOTE_EXCEPTION = - 1001 ; public static final int IABHELPER_BAD_RESPONSE = - 1002 ; public static final int IABHELPER_VERIFICATION_FAILED = - 1003 ; public static final int IABHELPER_SEND_INTENT_FAILED = - 1004 ; public static final int IABHELPER_USER_CANCELLED = - 1005 ; public static final int IABHELPER_UNKNOWN_PURCHASE_RESPONSE = - 1006 ; public static final int IABHELPER_MISSING_TOKEN = - 1007 ; public static final int IABHELPER_UNKNOWN_ERROR = - 1008 ; public static final int IABHELPER_SUBSCRIPTIONS_NOT_AVAILABLE = - 1009 ; public static final int IABHELPER_INVALID_CONSUMPTION = - 1010 ; public static final String RESPONSE_CODE = "RESPONSE_CODE" ; public static final String RESPONSE_GET_SKU_DETAILS_LIST = "DETAILS_LIST" ; public static final String RESPONSE_BUY_INTENT = "BUY_INTENT" ; public static final String RESPONSE_INAPP_PURCHASE_DATA = "INAPP_PURCHASE_DATA" ; public static final String RESPONSE_INAPP_SIGNATURE = "INAPP_DATA_SIGNATURE" ; public static final String RESPONSE_INAPP_ITEM_LIST = "INAPP_PURCHASE_ITEM_LIST" ; public static final String RESPONSE_INAPP_PURCHASE_DATA_LIST = "INAPP_PURCHASE_DATA_LIST" ; public static final String RESPONSE_INAPP_SIGNATURE_LIST = "INAPP_DATA_SIGNATURE_LIST" ; public static final String INAPP_CONTINUATION_TOKEN = "INAPP_CONTINUATION_TOKEN" ; public static final String ITEM_TYPE_INAPP = "inapp" ; public static final String ITEM_TYPE_SUBS = "subs" ; public static final String GET_SKU_DETAILS_ITEM_LIST = "ITEM_ID_LIST" ; public static final String GET_SKU_DETAILS_ITEM_TYPE_LIST = "ITEM_TYPE_LIST" ; public IabHelper ( Context ctx , String base64PublicKey ) { } public void enableDebugLogging ( boolean enable , String tag ) { } public void enableDebugLogging ( boolean enable ) { } public interface OnIabSetupFinishedListener { public void onIabSetupFinished ( IabResult result ) { } } public void startSetup ( final IabHelper . OnIabSetupFinishedListener listener ) { } public void dispose ( ) { logDebug ( "Disposing." ) ; mSetupDone = false ; if ( ( mServiceConn ) != null ) { logDebug ( "Unbinding<seq2seq4repair_space>from<seq2seq4repair_space>service." ) ; <START_BUG> if ( ( mContext ) != null ) <END_BUG> mContext . unbindService ( mServiceConn ) ; } mDisposed = true ; mContext = null ; mServiceConn = null ; mService = null ; mPurchaseListener = null ; } private void checkNotDisposed ( ) { } public boolean subscriptionsSupported ( ) { } public interface OnIabPurchaseFinishedListener { public void onIabPurchaseFinished ( IabResult result , Purchase info ) { } } IabHelper . OnIabPurchaseFinishedListener mPurchaseListener ; public void launchPurchaseFlow ( Activity act , String sku , int requestCode , IabHelper . OnIabPurchaseFinishedListener listener ) { } public void launchPurchaseFlow ( Activity act , String sku , int requestCode , IabHelper . OnIabPurchaseFinishedListener listener , String extraData ) { } public void launchSubscriptionPurchaseFlow ( Activity act , String sku , int requestCode , IabHelper . OnIabPurchaseFinishedListener listener ) { } public void launchSubscriptionPurchaseFlow ( Activity act , String sku , int requestCode , IabHelper . OnIabPurchaseFinishedListener listener , String extraData ) { } public void launchPurchaseFlow ( Activity act , String sku , String itemType , int requestCode , IabHelper . OnIabPurchaseFinishedListener listener , String extraData ) { } public boolean handleActivityResult ( int requestCode , int resultCode , Intent data ) { } public Inventory queryInventory ( boolean querySkuDetails , List < String > moreSkus ) throws IabException { } public Inventory queryInventory ( boolean querySkuDetails , List < String > moreItemSkus , List < String > moreSubsSkus ) throws IabException { } public interface QueryInventoryFinishedListener { public void onQueryInventoryFinished ( IabResult result , Inventory inv ) { } } public void queryInventoryAsync ( final boolean querySkuDetails , final List < String > moreSkus , final IabHelper . QueryInventoryFinishedListener listener ) { } public void queryInventoryAsync ( IabHelper . QueryInventoryFinishedListener listener ) { } public void queryInventoryAsync ( boolean querySkuDetails , IabHelper . QueryInventoryFinishedListener listener ) { } void consume ( Purchase itemInfo ) throws IabException { } public interface OnConsumeFinishedListener { public void onConsumeFinished ( Purchase purchase , IabResult result ) { } } public interface OnConsumeMultiFinishedListener { public void onConsumeMultiFinished ( List < Purchase > purchases , List < IabResult > results ) { } } public void consumeAsync ( Purchase purchase , IabHelper . OnConsumeFinishedListener listener ) { } public void consumeAsync ( List < Purchase > purchases , IabHelper . OnConsumeMultiFinishedListener listener ) { } public static String getResponseDesc ( int code ) { } void checkSetupDone ( String operation ) { } int getResponseCodeFromBundle ( Bundle b ) { } int getResponseCodeFromIntent ( Intent i ) { } void flagStartAsync ( String operation ) { } void flagEndAsync ( ) { } int queryPurchases ( Inventory inv , String itemType ) throws RemoteException , JSONException { } int querySkuDetails ( String itemType , Inventory inv , List < String > moreSkus ) throws RemoteException , JSONException { } void consumeAsyncInternal ( final List < Purchase > purchases , final IabHelper . OnConsumeFinishedListener singleListener , final IabHelper . OnConsumeMultiFinishedListener multiListener ) { } void logDebug ( String msg ) { } void logError ( String msg ) { } void logWarn ( String msg ) { } }

Fix:
if ( ( ( mContext ) != null ) && ( ( mService ) != null ) )